Medial rectus is one of the muscles of the orbit. It arises from the medial side of the common tendinous ring at the back of the orbit. It passes anteriorly to insert into the sclera of the eye anterior to the equator of the globe but posterior to the sclerocorneal junction.
It is innervated by the inferior division of the oculomotor nerve (CN III).
Medial rectus acts to adduct the eye.